The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Portable electronic and computing devices often rely on batteries to provide operational power when an external power source, such as an AC power adaptor, is not available. Although batteries are typically a reliable source of power, a voltage at which the power is provided varies as the battery discharges. Additionally, switching or transient loads on the battery may introduce noise (e.g., voltage ripple) on the power supplied by the battery. A power regulator of the device can compensate for the varying voltage and the noise of the power of the battery by regulating the battery-supplied power to a lower voltage.
This power regulator is effective so long as sufficient headroom is available between the voltage of the battery and the voltage of the regulated power. As the battery discharges and the voltage of the battery approaches that of the regulated power, however, the power regulator is unable to effectively reject the noise of the battery power. The noise of the battery power then passes through the power regulator to the components of the device, which are often not designed to tolerate this noise. The device, or components thereof, are typically powered-down or disabled when this condition occurs to prevent the components from attempting to operate when subjected to the noise. Thus, even when the battery has sufficient capacity to power the components of the device, the components are be powered-down to prevent the noise from disrupting the components.